The present invention relates to a braking system with master cylinder, decoupled from the brake pedal and hydraulic brake booster, comprising                a boost chamber into which the rear of the piston of the master cylinder is inserted, supplied in a controlled manner by a high pressure unit, supplying brake fluid under high pressure on command to the boost chamber in order to act on the piston of the master cylinder,        an actuator chamber receiving an actuator piston connected to the control rod of the brake pedal,        a controlled hydraulic link between the boost chamber and the actuator chamber.        
Numerous braking systems exist with a hydraulic brake booster arranged in series with the master cylinder. However, said known systems generally have the drawback of being relatively bulky and their design complex, as disclosed in the patent application US 2006/0158026 A1.